This invention relates to a sewing machine that is provided with a threading device for threading an eye in a needle with thread.
A sewing machine provided with a threading device is disclosed in Japan Published Unexamined Patent Application No. S63-89194. The threading device includes a stretching member for catching thread and stretching out the thread prior to threading, and a threading member such as a threading hook for threading a needle. In related-art sewing machines, an operator holds the end of thread and stretches the thread in front or at the rear of an eye in a needle. Subsequently, a threading hook is brought through the eye in the needle to hook the thread and thread the eye in the needle.
In the above related-art sewing machines, the threading hook is moved toward the eye in the needle for threading. Before the needle is thus threaded, a needle bar is raised to a position such that the threading hook can come through the eye in the needle attached to the end of the needle bar without contacting other component such as a presser foot assembly.
However, the related-art sewing machines have the following problem.
(1) The eye in the needle should be raised to a given position before the thread is stretched out in front or at the rear of the eye in the needle. Threading operation is thus intricate. PA1 (2) To put the thread onto a stretching member for stretching out the thread before the threading of the needle, an arm shaft is rotated. The needle may lower in its stroke according to the rotation of the arm shaft, and a thread guide attached to the needle bar lowers and draws thread from a bobbin or the stretching member, thereby loosening the thread. Since the thread cannot be stretched out at a given position, the threading member fails to thread the eye in the needle. PA1 (3) If the operator holds the end of the thread passed through the thread guide attached to the lower end of the needle bar and rotates the arm shaft to stretch out the thread at a given position, the needle may lower according to the stroke of the needle corresponding to the rotation of the arm shaft. The operator might be hurt at the lowering needle.
In the related art, the eye in the needle must be raised to the given position before the thread is stretched out.